As small measuring instruments which allow a measurer to carry out measurement by hand, for example, a dial gauge, a vernier calipers and a micrometer are known. These small measuring instruments have been also multi-functionalized, and thus various functions such as a wireless communication function have been installed thereon.
There are several types of multi-functionalized measuring instruments.
A first type is a type in which various functions are equipped in a measuring instrument. For example, a wireless communication function can be equipped. Since a measuring instrument is designed such that various functions are integrally equipped therein, completeness in product design is high and also operability is good.
However, all functions are not required for all users, and thus users, who need the wireless communication function, and users, who does not need the wireless communication function, exist. Therefore, a model, in which the wireless communication function is equipped, and a model, in which the wireless communication function is not equipped, are both manufactured and sold. However, this is not realistic to be developed in all types.
Thus, a type is also known, in which a connection port for a connector is provided in a measuring instrument and an external device is connected to the connection port via the connector (JP-A-2007-305055, JP-B-4456697 and JP-B-H07-086957).
However, there are restrictions on position, in which the connection port is provided, depending on types or sizes of measuring instruments.
In addition, the connected external device has not to become an obstacle in the way of measurement.
The small measuring instrument has the convenience of being capable of allowing measurement to be carried out while being grasped with one hand. However, a posture of grasping the measuring instrument is changed depending on an object to be measured or a site to be measured as well as a type of the measuring instrument.
Therefore, in JP-A-2007-305055, an external wireless communication device includes a connector, a wireless communication device and a flexible cable for connecting the connector to the wireless communication device. In the case of this configuration, a degree of freedom of arrangement of the wireless communication device is increased regardless of a position of the connection port due to the flexible cable.
Also, in an external wireless communication device disclosed in JP-B-4456697, a connector and a wireless communication device are configured as an integral unit. When the connector is inserted into a connection port, the wireless communication device is simultaneously fixedly attached to the measuring instrument. Since the wireless communication function is fixedly attached to the measuring instrument, operability is good.
Further, in JP-B-H07-086957, an external memory is configured to be freely detachably attached to the measuring instrument. The external memory has one rotation axis and a housing part thereof is configured to be rotated by 180°.